﻿/*
  KeePass Password Safe - The Open-Source Password Manager
  Copyright (C) 2003-2017 Dominik Reichl <dominik.reichl@t-online.de>

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.Text;

using KeePassLib.Delegates;
using KeePassLib.Interfaces;
using KeePassLib.Utility;

#if KeePassLibSD
using KeePassLibSD;
#endif

namespace KeePassLib.Collections
{
  public sealed class PwObjectPool
  {
    private SortedDictionary<PwUuid, IStructureItem> m_dict =
        new SortedDictionary<PwUuid, IStructureItem>();

    public static PwObjectPool FromGroupRecursive(PwGroup pgRoot, bool bEntries)
    {
      if (pgRoot == null) throw new ArgumentNullException("pgRoot");

      PwObjectPool p = new PwObjectPool();

      if (!bEntries) p.m_dict[pgRoot.Uuid] = pgRoot;
      GroupHandler gh = delegate (PwGroup pg)
      {
        p.m_dict[pg.Uuid] = pg;
        return true;
      };

      EntryHandler eh = delegate (PwEntry pe)
      {
        p.m_dict[pe.Uuid] = pe;
        return true;
      };

      pgRoot.TraverseTree(TraversalMethod.PreOrder, bEntries ? null : gh,
          bEntries ? eh : null);
      return p;
    }

    public IStructureItem Get(PwUuid pwUuid)
    {
      IStructureItem pItem;
      m_dict.TryGetValue(pwUuid, out pItem);
      return pItem;
    }

    public bool ContainsOnlyType(Type t)
    {
      foreach (KeyValuePair<PwUuid, IStructureItem> kvp in m_dict)
      {
        if (kvp.Value.GetType() != t) return false;
      }

      return true;
    }
  }

  internal sealed class PwObjectPoolEx
  {
    private Dictionary<PwUuid, ulong> m_dUuidToId =
        new Dictionary<PwUuid, ulong>();
    private Dictionary<ulong, IStructureItem> m_dIdToItem =
        new Dictionary<ulong, IStructureItem>();

    private PwObjectPoolEx()
    {
    }

    public static PwObjectPoolEx FromGroup(PwGroup pg)
    {
      PwObjectPoolEx p = new PwObjectPoolEx();

      if (pg == null) { Debug.Assert(false); return p; }

      ulong uFreeId = 2; // 0 = "not found", 1 is a hole

      p.m_dUuidToId[pg.Uuid] = uFreeId;
      p.m_dIdToItem[uFreeId] = pg;
      uFreeId += 2; // Make hole

      p.AddGroupRec(pg, ref uFreeId);
      return p;
    }

    private void AddGroupRec(PwGroup pg, ref ulong uFreeId)
    {
      if (pg == null) { Debug.Assert(false); return; }

      ulong uId = uFreeId;

      // Consecutive entries must have consecutive IDs
      foreach (PwEntry pe in pg.Entries)
      {
        Debug.Assert(!m_dUuidToId.ContainsKey(pe.Uuid));
        Debug.Assert(!m_dIdToItem.ContainsValue(pe));

        m_dUuidToId[pe.Uuid] = uId;
        m_dIdToItem[uId] = pe;
        ++uId;
      }
      ++uId; // Make hole

      // Consecutive groups must have consecutive IDs
      foreach (PwGroup pgSub in pg.Groups)
      {
        Debug.Assert(!m_dUuidToId.ContainsKey(pgSub.Uuid));
        Debug.Assert(!m_dIdToItem.ContainsValue(pgSub));

        m_dUuidToId[pgSub.Uuid] = uId;
        m_dIdToItem[uId] = pgSub;
        ++uId;
      }
      ++uId; // Make hole

      foreach (PwGroup pgSub in pg.Groups)
      {
        AddGroupRec(pgSub, ref uId);
      }

      uFreeId = uId;
    }

    public ulong GetIdByUuid(PwUuid pwUuid)
    {
      if (pwUuid == null) { Debug.Assert(false); return 0; }

      ulong uId;
      m_dUuidToId.TryGetValue(pwUuid, out uId);
      return uId;
    }

    public IStructureItem GetItemByUuid(PwUuid pwUuid)
    {
      if (pwUuid == null) { Debug.Assert(false); return null; }

      ulong uId;
      if (!m_dUuidToId.TryGetValue(pwUuid, out uId)) return null;
      Debug.Assert(uId != 0);

      return GetItemById(uId);
    }

    public IStructureItem GetItemById(ulong uId)
    {
      IStructureItem p;
      m_dIdToItem.TryGetValue(uId, out p);
      return p;
    }
  }

  internal sealed class PwObjectBlock<T> : IEnumerable<T>
      where T : class, ITimeLogger, IStructureItem, IDeepCloneable<T>
  {
    private List<T> m_l = new List<T>();

    public T PrimaryItem
    {
      get { return ((m_l.Count > 0) ? m_l[0] : null); }
    }

    private DateTime m_dtLocationChanged = TimeUtil.SafeMinValueUtc;
    public DateTime LocationChanged
    {
      get { return m_dtLocationChanged; }
    }

    private PwObjectPoolEx m_poolAssoc = null;
    public PwObjectPoolEx PoolAssoc
    {
      get { return m_poolAssoc; }
    }

    public PwObjectBlock()
    {
    }

#if DEBUG
    public override string ToString()
    {
      return ("PwObjectBlock, Count = " + m_l.Count.ToString());
    }
#endif

    IEnumerator IEnumerable.GetEnumerator()
    {
      return m_l.GetEnumerator();
    }

    public IEnumerator<T> GetEnumerator()
    {
      return m_l.GetEnumerator();
    }

    public void Add(T t, DateTime dtLoc, PwObjectPoolEx pool)
    {
      if (t == null) { Debug.Assert(false); return; }

      m_l.Add(t);

      if (dtLoc > m_dtLocationChanged)
      {
        m_dtLocationChanged = dtLoc;
        m_poolAssoc = pool;
      }
    }
  }
}
